Introduction and Background

Biochar temperature versus characteristics
Some researchers believe that the best biochar is formed by low temperature pyrolysis at about 500˚ C, with higher temperature pyrolysis producing a more traditional charcoal. Five hundred degrees C seems to be high enough to achieve maximal surface area but also low enough to retain some bio-oil condensate. Credit: Temperature effects on carbon recovery, CDC, pH and surface area, Lehmann (2007), Front. Ecol. Environ. 5:381-387

As the world’s population rises, people will continue to put more pressure on their terrestrial landscapes in order to extract food, fiber, and fuel to meet their growing needs. At the same time that populations drive a need to find methods of more efficient agricultural land use the climate is changing and land degradation is an increasing problem. In the industrialized world, modern agriculture relies on heavy chemical inputs and creates pollution problems in our waterways and our air. Carbon dioxide, methane, and nitrous oxide are byproducts of modern agriculture that exacerbate climate change. In the developing world farmers often do not have access to the expensive chemical inputs of modern agriculture and thus rely on ‘slash and burn’ techniques. These practices volatilize most of the nutrients accumulated in biomass and cause air quality concerns. Alternatively, farmers may incorporate organic wastes that have short residence times in soil, thereby releasing large amounts of methane and other greenhouse gasses as they decompose. In both systems of agricultural production, nutrient cycles are very leaky with nutrients entering the system and then quickly leaving through leaching, volatilization, erosion, and crop removal. [Read more…]